Abstract We present results of the study of the large scale distribution of galaxies up to z ~ 0.8 in the field HS 47.5–22 based on the photometric data obtained with the 1 m Schmidt telescope of the Byurakan astrophysical observatory (BAO NAS). The complete sample includes 28 398 galaxies brighter than \({{m}_{{{\text{AB}}}}} = {{23}^{{\text{m}}}}~\)up to \(z \sim 0.8\). Clusterings of density in

Abstract—We analyze the spatial and kinematic properties of a large sample of young T Tauri type stars in a 500 pc radius solar neighborhood, closely related to the Gould belt. The following parameters of the exponential density distribution have been determined: the average \({{({{z}_{{\text{G}}}})}_{ \odot }} = - 25 \pm 5\) pc and scale height \({{h}_{{\text{G}}}} = 56 \pm 6\) pc. We propose a method

Abstract—The paper presents complete results of measurements of the magnetic-field longitudinal component Be and radial velocities VR for 163 objects, mainly main-sequence chemically peculiar stars and standards. Observations were carried out in 2012 at the 6-m BTA telescope using the Main Stellar Spectrograph (MSS) equipped with a Zeeman analyzer. Six new chemically peculiar magnetic stars were discovered:

Abstract—This study continues the investigation of the super-fast variability of line profiles in the spectra of stars of early spectral classes performed in 2017 and 2018. We investigated the variability of line profiles in the spectra of OBA stars with the SCORPIO multi-mode focal reducer at the 6-m SAO RAS telescope (BTA). Short-period regular variations of the H and He lines were detected in the

Abstract—This paper presents a method for searching for polar candidates using mid-band filters. One of the spectral features of polars is the HeII λ4686 strong emission line. We selected the Edmund Optics color filters with central wavelengths of 470, 540, and 656 nm and a transmission bandwidth of 10 nm. These filters cover the regions of the HeII λ4686 line, continuum, and the Hα line respectively

Abstract We present the results of determination of the age, helium mass fraction (Y), metallicity ([Fe/H]), and abundances of the elements C, O, Na, Mg, Ca, Ti, Cr and Mn for 26 globular clusters of the Galaxy. In this work, we apply a method developed by us that employs medium-resolution integrated-light spectra of globular clusters and models of stellar atmospheres and it is supplemented in this

Abstract—The star-forming regions (SFRs) in the peculiar galaxies NGC 660, NGC 1512, NGC 4395 and NGC 4618 are studied. The relationships between such characteristics of star forming regions as UV, near- and far-IR fluxes, as well as in the Hα and HI lines, surface brightness in these ranges, and the scatter of the radial velocities of ionized and neutral hydrogen are considered. It is shown that in

Abstract—This work is a continuation of the studies of the ultrafast variability of line profiles in the spectra of early-type stars. Line profile variations in the spectrum a chemically peculiar A0Vp star α2 CVn are investigated using the January 6, 2020 observations carried out with the 6-meter BTA telescope at SAO RAS equipped with the MSS spectrograph. Regular short-term periodic variations of

Abstract—The article presents the results of multicolor photometry, medium and low resolution spectroscopy of the red nova V838 Mon remnant for 16 years after the 2002 outburst. We also used the archival photometry with the photographic plates of the Sonneberg and Moscow collections from 1928 to 1994. Analysis of these observational data confirmed that the progenitor of the V838 Mon explosion was a

Abstract—Modern Multimessenger Astronomy is a powerful instrument for performing crucial tests of the Standard Cosmological Model in the wide redshift interval up to z ∼ 10. This testing is principally important for discussion related to discrepancies between local and global measurements of cosmological parameters. We present a review of multimessenger gamma-ray burst observations currently performed

Abstract We provide an analytical description of the method for the determination of the coordinates of solar radio sources from multi-azimuth observations on RATAN-600. We analyze models of the displacement of the object across the scan depending as a function of azimuth taking into account solar rotation and suggest a method for estimating the rate of displacement due to rotation. We demonstrate

Abstract We use the data of our extended catalog of spectroscopic determinations of elemental abundances in the atmospheres of Galactic-field RR Lyrae type variables to show that metal-rich RR Lyraes ([Fe/H] > −1.0) have anomalous abundances of some elements. In particular, the relative abundances of scandium, titanium, and yttrium in metal-rich RR Lyrae type variables are lower than the corresponding

Abstract—Using the data from the second release of the Gaia exoatmospheric astrometric observatory archive the structure of the Cas5 OB association and the parameters of stars of extremely high luminosity that it contains have been refined. Two groups of OB stars have been isolated in the direction of the association at distances 3.3 and 4.3 kpc.

Abstract—The variability of radial velocities, equivalent widths and central line depths in the spectrum of the κ Cas supergiant was studied using CCD coude-echelle spectra with high spectral resolution and signal-to-noise ratio. The radial velocity variability of all the studied lines is due to non-radial pulsations. The variability parameters (period P, amplitude A and average value γ) of radial

AbstractMillimeter- and submillimeter-wave maps are used to select potential candidate objects with the Sunyaev–Zeldovich effect in the vicinity of RCR (RATAN Cold Refined) radio sources. The properties of “hot” and “cold” spots in the right-ascension interval 2h ≤ RA ≤ 17h and the declination strip \({\text{De}}{{{\text{c}}}_{{2000}}} = 45^\circ .9' \pm 15'\) are studied. In the entire strip a total

Abstract—Observations of facular areas of the Sun using the Helioseismic and Magnetic Imager device of the Solar Dynamics Observatory allow detecting long-period oscillations in the magnetic field of facular knots with periods ranging from 30 to 250 minutes. Statistically significant oscillation modes are selected by the method of time series decomposition in empirical modes. During the observation

Abstract—In the paper the possibility of the presence of a non-thermal component described by a power law spectrum in the X-ray spectra of OB stars is investigated. The low-resolution spectra of 101 OB stars obtained using the EPIC camera on the XMM satellite are analyzed. It is concluded that the contribution of the non-thermal component of X-ray emission can be significant and even determining for

Abstract—We critically review the results of earlier studies on magnetic stars with anomalous helium lines. We discuss the issues associated with the fossil-field theory and the scenario of the formation of magnetic stars. A special feature of the results of our study is that they are derived from more than 160 direct estimates of average surface magnetic fields Bs or models obtained by the method

Abstract—The paper analyzes the origin for the separation of gas-and-dust disks around young stars into two large groups: those with circular and spiral structures. Such a separation of disk structures is explained by the existence of stable and unstable gas-dynamic equilibrium of protostellar envelopes. A model of wave disturbances of the gas-dust protostellar envelopes is constructed. The equation

AbstractEnceladus is an attractive place to look for signs of life thanks to liquid water and the availability of energy. Recent research has proven that the ejected material of Enceladus south pole consists of water vapor, water ice, carbon dioxide, methane and molecular hydrogen. Possible similarities of physical and chemical conditions between Enceladus ocean bottom and the carbonate mineral matrix

Abstract—Based on archived images from the Hubble Space Telescope, stellar photometry of the dwarf galaxy Coma P, located near the Virgo galaxy cluster, was performed. The selection of weakly luminous regions of the galaxy showed that Coma P consists of two interacting dwarf galaxies, one of which has a weak star formation, and the second galaxy has a very low surface brightness, there is no star formation

Abstract—This paper presents the functional design of “Quantochron 5-48” high temporal resolution system for multidimensional chronometration of stochastic fluxes. The device can determine the photon arrival times by array detectors and the accompanying spatial, spectral, and polarization characteristics of these photons, with a sampling time of 10 nanoseconds and the accuracy of UTC calibration provided

AbstractWe calculate models of extended stellar atmospheres with a temperature in the range of 12 000–40 000 K and a mass loss rate of \({{10}^{{ - 6}}}\)–\({{10}^{{ - 4}}}{{M}_{ \odot }}\)\({{{\text{yr}}}^{{ - 1}}}\). A large number of objects with emission spectra, such as luminous blue variables, FeII—emission line stars, Of/late-WN stars, and even ultraluminous X-ray sources often have effective

Abstract—We report the results of laboratory tests of the first version of the high-resolution fiber-fed spectrograph designed for the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). During laboratory tests a spectral resolution of about 70 000 was achieved. The peak efficiency of the entire optical path of the spectrograph (without light losses at the CCD, primary mirror

Abstract—We use the archival data obtained with the Hubble space telescope to measure distances by the tip of the red-giant branch (TRGB) method to SNIa parent galaxies. Our sample consists of four galaxies: NGC2841, NGC4496A, NGC4535, and NGC4527. For three of them, we were able to determine only the lower bounds of the distance. For the galaxy NGC4527, we estimated the TRGB distance modulus: (m − M)0

AbstractThe correlation between the data obtained with two gravitational wave (GW) detectors (in Rome and in Maryland) and two neutrino detectors (LSD in Italy and Kamiokande in Japan) has been studied in more detail. If we indicate with U1 the response of the gravitational wave detectors and with U2 the response of the neutrino detectors, we find that there is a clear time correlation between U1 and

Abstract—We present the Hα images of ultra-flat (UF) spiral galaxies seen practically edgeon. The galaxies have the angular diameter in the B band \(a > 1.9' \) and the apparent axial ratio (a/b) > 10. We found that their Hα images look, on average, almost two times thinner than those in the red continuum. The star-formation rate in the studied objects, determined from the Hα flux, is in good agreement

Abstract—We report the development of a photosensor device based on a position-sensitive detector with a gallium arsenide (GaAs) cathode and a 16-element anode. In the case of asymmetric heterostatic circuit (electrodes combined in fours) its working field was limited by 10 mm (for a 18-mm photocathode). Implementing a scheme of analog coding of the coordinates of the centroids of electron avalanches

Abstract—Using modern published data on velocities and spectroscopic definitions of chemical elements in stellar objects of the Galaxy, we investigated the relationship of chemical composition with the kinematics of different populations. The paper shows that the old stellar populations of the Galaxy, belonging (by the kinematic criterion) to the thick disk subsystem—globular clusters, field variables

Abstract—We report the results of a detailed study of the central part of the Seyfert galaxy Mkn938. Observational data were obtained with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences using integral field spectrograph MPFS and a scanning Fabry–Perot interferometer. Mkn938 is interesting for being a result of a merger of two gas-rich galaxies, and we

Abstract—Requirements to a modern computer network of a research organization, in particular, to the local-area network of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) are described. The choice of the direction of the development of primary tools for supporting the observing process and based on local network infrastructure services of SAO RAS is defined. This

Abstract—We present a method of determination of numbers of gyroresonance layers most effectively radiating in the transition region of the active solar atmosphere. It is based on determination of frequency in the spectrum of an extraordinary wave of an active region, at which the gradient of this spectrum abruptly rises. Observations of 29 active regions carried out at the RATAN-600 radio telescope

Abstract—A detailed study of comets active at large heliocentric distances (greater than 4 au) which enter the Solar System for the first time and are composed of matter in its elementary, unprocessed state, would help in our understanding of the history and evolution of the Solar System. In particular, contemporary giant planet formation models require the presence of accretion of volatile elements

The improvement of the calibration relation for determining the size of the broad-line region from the observed optical luminosity of active galactic nuclei (AGN) is a necessary task to study fundamental parameters of distant AGNs such as mass of the central supermassive black hole. The most popular method of the BLRsize estimation is the reverberation mapping based onmeasuring the time delay between

The spectral properties of inhomogeneities of the cosmic microwave background are considered. The inhomogeneity spectra are studied in the frequency range from 30 to 217 GHz according to multi-frequency maps of the Planck space mission with smoothing at different angular sizes. According to the thermodynamic temperature versus frequency relation, it is shown that the map at 70 GHz has a signal distribution

We conducted the stellar photometry using the archive images of the Hubble Space Telescope of the dwarf irregular galaxy Cas 1 located near the Milky Way. Blue supergiants detected in the obtained Hertzsprung-Russell diagram are concentrated in star-forming regions. We found that the red star branch consists of numerous AGB stars and a small number of brighter red supergiants. In the luminosity function

Gigahertz-Peaked spectrum (GPS) sources are compact active galactic nuclei, presumably young precursors of bright radio sources. The study of GPS radio properties provides information about the features of synchrotron radiation in extragalactic sources. Also in applied research, GPS sources are useful as compact stationary radio sources in the sky for astrometric purposes. This paper presents the results

A comprehensive statistical analysis of the relationship between the chemical and spatially kinematic parameters of the globular clusters of the Galaxy has been performed. The data of the author’s compilation catalog contain astrophysical parameters for 157 clusters and the relative abundances of α-elements for 69 clusters. For 121 clusters, the data are supplemented by spatially kinematic parameters

We study the nearest outskirts (R < 3R200c) of 40 groups and clusters of galaxies of the local Universe (0.02 < z < 0.045 and 300 km s-1 < σ < 950 km s-1). Using the SDSS DR10 catalog data, we determined the stellar mass of galaxy clusters corresponding to Ks-luminosity (which we determined earlier based on the 2MASX catalog data) (M*/M⊙) ∝ (LK/L⊙)1.010±0.004 (MK < - 21m.5, R < R200c). We also found

The paper describes a target setting of searching for apsidal motion in 21 eclipsing binaries. We estimate the capability of its determination for the systems of interest in the coming years, as well as present results of observations in 2009–2018, in which the minima of the light curves of these stars have been obtained. The accuracy of orbital period determination of the studied binaries is 10–100

We present the results of methodological works on automated analysis of the large scale distribution of galaxies. Selecting candidates for clusters and groups of galaxies was carried out using two complementary methods of determining the density contrast maps in the narrow layers of the three-dimensional large scale distribution of galaxies: the filtering algorithm with an adaptive core and the Voronoi

We analyze the long-term activity of a little known dwarf nova (DN) DT Oct. We use photographic observations from the Bamberg Observatory (Southern Patrol Photographic Sky Survey), CCD data from ASAS-3 survey, and AAVSO data (both CCD and visual). We determined the recurrence times of the superoutbursts, TCso, and of the normal outbursts, TCno, to be approximately 311 d and about 30 d, respectively

We present an analysis of the spectra of the star V837 Tau, which belongs to a class of chromosphere-active RSCVn type stars. The observational material was obtained with the 1.5-m Russian-Turkish telescope RTT-150 and the 2.6-m Shajn telescope of the Crimean astrophysical observatory. To reveal signs of the photosphere spottedness of the primary and to isolate the faint secondary, we performed the

We study relations of the parameter Rvar (amplitude of the brightness variability, stellar activity indicator) with respect to the effective temperature and the period of rotation of stars belonging to the A–M spectral types. A common dataset gives an idea of variations in this parameter for stars with convection. It was confirmed that the limit of applicability for the gyrochronological relation PtM

The precise determination of the physical and dynamical parameters of the HIP 109951 triple star system (WDS J22161-0705AB) which is formed by the A, Ba, and Bb components are presented. The binary nature of component B was recently confirmed by studying the radial velocities. The analysis of the system follows Al-Wardat's complex method for analyzing CVBS which employs Kurucz (Atlas9) line blanketed

We present the results of long-term spectral monitoring of yellow hypergiants (YHGs) of northern hemisphere with a R ≥ 60 000 resolution. The spectra of these F–G stars of extreme luminosity, compactly located at the top of the Hertzsprung–Russell diagram revealed a variety of spectral features: various types of Hα profile, the presence (or absence) of forbidden and permitted emissions, as well as

A method of “self-calibration” of two sectors of the RATAN-600 radio telescope based on synchronous measurements of strong extragalactic sources, including variable ones, is proposed. The method gives refined corrections to the standard calibration of each of the telescope’s sector. It is based on the fact that ideal synchronous independent measurements of the same object should give the same results

We have surveyed about a hundred papers published in 2018 in the leading astronomical journals and related to the “Magnetic fields and physical parameters of chemically peculiar and related stars” subject area. We have considered new projects of telescopes and mounted instruments for them as well as the first results obtained with telescopes recently put into operation. We have reviewed new papers

The paper presents the statistical data analysis of radio astronomic surveys in the sky region of a size of 177▭°at high galactic latitudes. We divided the region into four sectors equal in area and analyzed the observed properties of radio sources and the cosmic microwave background in each sector. The distribution of physical parameters (flux density, radio spectrum type, spectral index of radio

Stellar photometry in nine fields around the giant elliptical galaxy M87 in the Virgo cluster is obtained from archival images of the Hubble Space Telescope. The resulting Hertzsprung-Russell diagrams show populated red-giant and AGB branches. The position of the tip the red-giant branch (the TRGB discontinuity) is found to vary with galactocentric distance. This variation can be interpreted as the

We investigate some aspects of Galactic disc kinematics based on the data on open clusters from the current version of “The Homogeneous Catalog of the Main Parameters of Open Star Clusters” and from Gaia DR2. Based on the radial velocity and proper motion data for the clusters we determine the angular velocity of the Sun in the Galaxy as Ω0 = 25.6 ± 1.2 km s-1 kpc-1. A new approximation of the Galactic

We present an optical spectrum of the star V1648 Aql (IRAS19386+0155) obtained at the 6-m SAO RAS telescope with a spectral resolution of R ≥ 60 000. Heliocentric radial velocity was measured from numerous metal absorptions is Vr = 10.18 ± 0.05 km s-1 (VLSR = 18.1 km s-1). We determined the atmospheric, circumstellar, and interstellar components in the profile of the Na I D lines at Vr = 9.2, -3.4

We present a study of the parameters of objects belonging to a sparsely populated group of FKCom-type stars, as well as a brief review of our earlier studies dedicated to the search for stellar candidates of this type. We consider the data for another new candidate-the star KIC 7739728. The light curve of this star clearly demonstrates properties of regular rotational modulation, the rotation exhibits

Magnetic-field measurements for Herbig Ae/Be stars are analyzed to determine the distribution functions of root-mean-squared magnetic field strengths \(\mathcal{B}\) (in G) and magnetic fluxes Φ (in G cm2) for Herbig stars with measured magnetic field. The \(\mathcal{B}\) and Φ values are approximated by log-normal functions with the means equal to 〈log \(\mathcal{B}\)〉 = 2.0 and log 〈Φ Φ〉 = 25.5,

We present the results of spectral observations of the Herbig Ae/Be star HD179218. We discovered a wave-like variation in the parameters of the Hα line emission component with a typical time scale of about 40 days. The observed wave is characterized by a significant decrease in the measured line parameters, with conspicuous branches of increasing and decreasing parameters. Simultaneously, additional

A technique for computing the spectrograph for astrophysical studies based on the basic input and output parameters of the optical system. In the framework of the proposed technique, it is possible to determine the main properties of the spectrograph components: the focal length of the collimator, the focal length of the projection camera, the blaze angle of the grating, the frequency of the grating

We present the photometric and spectroscopic observations of the polar 1RXSJ152506.9-032647. The observations were carried out at the 6-m and Zeiss-1000 telescopes of the SAO RAS, and at the 1.5-m Russian-Turkish telescope RTT150. The determined orbital period of the system is \(0\mathop .\limits^{\rm{d}} 06462793\). The object was observed in the intermediate \(\langle{R_c}\rangle=17\mathop .\limits^{\rm{m}}8\)

Polarimetric studies in astronomy have currently acquired great importance. They are used to study magnetic fields of stars, determine the orientation of orbits of exoplanets, reflection effects in stellar atmospheres and accretion disks, and many other things. This paper presents a computation of optical arrangements of Stokes polarimeters with different polarization analyzers. A preliminary estimate

Analysis of the time series of climatic characteristics of the Crimean peninsula for the period of 19832-2005 showed an enhanced growth (compared to other points of the Crimea) of the insolation of the Earth’s surface at Kara-Dag and an anomalous temperature decrease of the Earth’s surface at the Cape Fonar. The parameters of the geomagnetic field of the Kara-Dag mount were estimated. To derive the

We have studied the interstellar lines and diffuse bands in the spectrum of the supergiant κ Cas using the CCD spectra obtained with the Echelle spectrograph of the 2 meter telescope at the peak Terskol observatory. A synthetic stellar spectrum was used to correctly reveal the interstellar features, computed for a model atmosphere with Teff = 21 500 K, log g = 2.60, v sin i = 83 kms-1, [M/H] = 0.0